Asbestos separating



Get. 9, 1945. 1 c. PHARO ASBESTOS SEPARATING Filed March 26, 1945 /N VENTOR LEE C. PHARO omlx rToR/vsy 5x6 L .QQ

Patented @et 9, i945 ASBESTOS SEPARATING Lee C. Pharo, Thetford Mines,Quebec, Canada,

assignor to Johnsons Company,

Thetford Mines, West, Quebec, Canada Application March` 26, 1943, SerialNo. 480,700

Claims. (Cl. 209-2) Introduction This invention relates to the treatmentof brous materials and more particularly to the removal of unberizedspicules or lumps of foreign matter therefrom. It has specialapplication to the treatment of asbestos.

When asbestos has been milled and berized it may still contain lumps orspicules of unflberized or only partially berized material which havedetrimental results when the fiber is employed for textile and otheruses. Owing to the fibrous nature of asbestos, it is difcult to separatethese lumps from masses of the fberized product, especially if this isto be done without injury to the relatively brittle ber. 'I'hese remarksapply with greater or `lesser degree to other fibrous materials.

Objects Having regard to the foregoing, it is a principal object of thepresent invention to provide a method and means for removing lumps orcoarse aggregates from partially or substantially completely berizedfibrous materials, particularly asbestos. It is a further object toprovide a method of this nature in which the lumps can be removed fromthe material without injury thereto. It is a still further object toprovide an apparatus for performing these functions which is convenientto construct and to operate.

With these and other objects in view, a characteristic embodiment of theinvention is inherent in the following procedure. The ber in asubstantially dry state after having been milled and ben'zed, isconveyed in masses forming a layer on a moving surface havingperforations adapted to permit the escape therethrough of heavy lumps ofmaterial or foreign matter without allowing the escape of the beritself. While it is being advanced on this conveyor, the material isstirred and moved about locally in relation to the conveyor in such amanner as to cause gravitation of the heavy lumps to the bottom of themasses. The agitation also causes this material to gravitate through theopenings in the conveyor. The net result of the treatment is in removingthe greater portion of the lumps from the mass being treated Withoutinjury to this material.

Detailed description The invention will be understood more specically byreference to the following detailed description illustrated by theaccompanying drawing showing preferred equipment used in carrying out aspecific embodiment of the invention, and in which:

Figure l is a side elevationv of the preferred apparatus.

Figure 2 is a plan view of the apparatus shown in Figure 1.

Figure 3 is an end view of the apparatus shown in Figures 1 and 2.

Figure 4 is an enlarged plan View of one of the boWS. l

Figure 5 is an elevation of the bow shown in Figure 4.

Referring more particularly to the drawing, the apparatus includes anelongated frame A having a pair of parallel supporting beams IIconstituting a base. Long uprights I5, I8 and shorter uprights 20 and22, extend upwards from each beam II. A pair of parallel horizontalbeams 30 are supported by the uprights I5 etc. Several discharge hoppers3l, 32, and 33 are mounted in the frame lengthwise thereof. As indicatedin the drawing, the top edges of these hoppers lie at one side of thebelt and just underneath it. The hoppers slope to the other side of themachine adjacent the bottom thereof so that foreign substancesgravitating from the belt are carried to the side of the machine as willbe described. Pairs of bearing blocks 40 and 42 are mounted adjacent theextremities of the beams 30. Journalled in these blocks are bearingscarrying shafts 50 and V55 respectively. On the shaft 50 is mounted aconveyor drum preferably of cast iron. On the shaft 55 is mounted asimilar conveyor drum 6I. Intermediate the bearing blocks 40 and 42 onthe beams 30 are mounted bearing blocks 60, 6I, 62, 63 and 64, eachcarrying an idler 10, 1I, 12. 'I3 and 'I4 respectively, extending thewidth of the apparatus. Intermediate the ends thereof are also mountedthe bearing blocks and 8l carrying return idlers 82 and 83 respectively.An endless conveyor belt extends about the drums 60 and 6I and issupported intermediate these drums by the idlers 'I0 etc. and 83 etc.For handling asbestos, this belt is preferably of rubber and isperforated to allow the escape therethrough of foreign substances orlarge lumps of fiber which it is a purpose of the present process toremove.

A series of springs |00, IIJI, |02 and |03, four on each side of themachine are spaced apart and connected to each beam II and extendupwardly therefrom. These springs are preferably of wood, because of itslongevity in such applications, and shaped as indicated. Carried by thesprings and connected to the upper end thereof at each side of themachine are parallel wooden shaker arms adapted by their mounting on thesprings |00, etc. for limited reciprocal movement lengthwise of theapparatus in a plane determined by the length of the springs. Mountedbetween the arms ||0 is a series of steel bows |20, |20a etc. The bowsare preferably U-shaped and preferably made of flexible steel. The endsare parallel to and bolted to the arms ||0 and the intermediate portionsextend between the respective arms I|0. The bows are parallel to oneanother and spaced apart along the entire length of the arms. On eachbow is mounted several downwardly extending spaced apart fingers |23.These fingers extend toa position close to the conveyor belt leavingonly a slight clearance.

Also mounted on the frame adjacent the upper ends of the uprights I5 andI8 are a pair of bearing blocks |30 one at each side of the machine.Journalled in bearings in these blocks is a drive shaft |35 extendingthe width of the machine.

Mounted on the drive shaft, one at each side of the apparatus, areeccentrics |40. The eccentrics are mounted with the high sides 180 fromeach other. Connected to each eccentric is one end of an arm |45, theother end of which is connected as at |46 to one of the shaker arms ||0.

On the top of the beams I5 and I8 are mounted a pair of beams |50.Between the beams |50 extend cross beams |5I. On thebeams |5|intermediate the beams |50 is mounted an electric motor |53. On theshaft |35 is mounted a sprocket gear |55. A sprocket drive chain extendsfrom the motor sprocket to the sprocket |55. Sprockets |50 and |6| andthe chain |55 extending between these sprockets constitute a drivingconnection between the shaft |35 and the conveyor shaft 50. In this way,the shafts |35 and 50 are driven from the electric motor. The speed isadjusted by the sizes of the respective drive pulleys or sprockets.

'I'he conveyor has been described as extending horizontally because goodresults are thus achieved. A sloping conveyor might be used to achievesimilar results without departing from the spirit of the invention.

Operation The material to be treated is fed from the spout |60 on to thefeed end of the belt 90 and is conveyed by this belt from left to rightof the apparatus (as viewed in the ligure) At the same time, the arms|I0 are being reciprocated oppositely by the eccentric arrangementdescribed above so that; the flexible bows |20 are being moved back andforth across the belt causing the fingers to describe arcuate paths backand forth adjacent the surface of the belt closely resembling the actionof the fingers of a human hand stirring up fibrous material on a flatsurface. 'I'he fingers coming into contact with the material being movedforward by the belt have the eilect of stirring up or raking the fibrousmass and causing any heavy particles, aggregates or lmps such asspicules of ber or foreign matter to gravitate to the bottom of the massand eventually to fall through the openings 9| in the belt. 'I'heflberized material itself will not pass through the openings in the beltbecause of its fibrous nature but will nearly all remain on the surfaceof the belt, until it is discharged to a discharge spout |80.

Where asbestos is treated this has the effect of removing foreign mattersuch as sand or any other material which might have become entrained inthe masses during their previous treatment. It also serves importantlyto separate spicules of the fiber itself, which may not; have beencompletely iiberized in the previous operations and which, if left inthe mass, would cause trouble during the textile operations.

In the treatment of iiberzed chrysotile asbestos,

" for instance, that coming from treatment in an apparatus such as thatdescribed in U. S. Patent No. 2,219,077, a preferred operating speed ofthe belt is about 200 feet per minute, although this speed is notgenerally critical. A preferred operating speed for the shaft |35 isabout, 200 R. P. M. where the belt is about 24 inches in width. This canalso be varied Within Wide limits. The thickness of the layer of fiberon the belt is preferably in the neighborhood of about 3 inches to about31A inches. According to the conditions enumerated, in runs in which 20short tons of asbestos were treated, about 900 pounds of lumps wereremoved, in other words in the neighborhood of 21A%. A preferred type ofconveyor belt is of rubber and includes perforations about positioned atabout centers. According to this preferred construction, the fingers areof wood or ebonite. These fingers may, of course, be of other materials,but if metal is used there is the possibility of broken pieces gettingin the subsequent operations and causing damage to the machinery.

Advantages An important advantage of this invention is that there may beremoved from a fibrous material, in a more or less ilberized state,lumps either of the material itself or of foreign matter entrainedtherein without injury to the material. The treatment might be likenedto that of the shaking imparted to a mass of asbestos by hand, using thefingers to agitate it. In this way, the material is continually spreadover local areas of the surface in eccentric directions, and the mass isconstantly stirred up and caused to take up different positions. Thishas the effect of causing the dust and any lumps present to gravitate tothe bottom and also of pushing the lumps through the holes in theconveyor. By this method, therefore, there is produced a ber which hassuperior characteristics especially for textile use wherein the presenceof lumps would have a serious effect on the textile qualities of thefiber and would result in disruption of textile operations.

It will be understood that, Without departing from the spin't of theinvention or the scope of the claims, various modifications may be madein the specc expedients described. The latter are illustrative only andnot offered in a restricting sense.

'Ihe sub-titles used throughout the specification are merely to simplifyreference thereto and should otherwise be disregarded.

I claim:

1. An apparatus for treating fibrous materials containing lumps,comprising, a perforated conveyor adapted to advance the materialthrough an extensive path, means for depositing a loose mass of thematerial on said conveyor, and stirring means in said path for stirringsaid material and moving it eccentrically in local areas of saidconveyor as it is being advanced whereby lumps are caused to gravitateto the bottom of said masses and through the openings in said conveyor,said stirring means including a series of flexible members arranged oversaid conveyor and substantially parallel to the surface thereof, saidexible members including ngers extending downwardly to points adjacentthe surface of said conveyor, and means for exing said flexible memberswhereby the ngers are caused to move locally in eccentric directionsover said surface whereby the material is spread over said local areas.

2. An apparatus as claimed in claim 1 wherein said flexible members area series of substantially U-shaped bows arranged over said conveyor.

3. An apparatus for treating brous materials containing lumps,comprising, a perforated conveyor adapted to support masses of thematerial and to convey it through an elongated path, means fordepositing masses of material on said conveyor, a pair of shaker armslying substantially parallel to the surface of the conveyor and at eachside thereof, substantially U-shaped members each having an endconnected to one of said shaker arms, fingers extending downwardly fromsaid U-shaped iiexible members to points adjacent the surface of saidconveyor, means for reciprocating said arms oppositely whereby saidU-shaped flexible members are flexed to cause the ngers to moveeccentrically adjacent the conveyor to stir the masses supportedthereby. A

4. An apparatus as claimed in claim 3 including means beneath saidconveyor for removal of lumps gravitated through said conveyor and meansadjacent the discharge end of said conveyor for receiving said massesafter removal of the lumps therefrom.

5. An apparatus for treating fibrous materials containing lumps,comprising, a conveyor adapted to support masses of the material and toconvey it through an elongated path, the surface of said conveyor havingopenings therein adapted for the escape therethrough of extraneous lumpsbut to exclude the fibrous material proper, means4 for depositing massesof material on said conveyor surface, a pair of shaker arms lyingsubstantially parallel to the surface of the conveyor and at each sidethereof, flexible members extending between said shaker arms andconnected thereto, fingers extending downwardly from said members topoints adjacent the surface of said conveyor, means for reciprocatingsaid arms oppositely in a plane substantially parallel to said conveyorsurface whereby said members are flexed to cause the ngers to moveeccentrically close to the conveyor surface to spread the massesthereover in eccentric directions.

6. An apparatus for treating fibrous materials containing lumps,comprising, a perforated conveyor adapted to support masses of thematerial and to convey it through an elongated path, means fordepositing masses of material on said conveyor, a pair of shaker armslying substantially parallel to the surface of the conveyor and at eachside thereof, flexible members extending between said shaker arms andconnected thereto, ngers extending downwardly from said ilexible membersto points adjacent the surface of said conveyor, means for reciprocatingsaid arms oppositely whereby said flexible members are .flexed to causethe fingers to move eccentrically adjacent the conveyor surface tospread the masses thereover.

7. An apparatus for treating fibrous materials containing lumps,comprising, a frame, a perforated conveyor mounted on said frame andadapted to convey them through an elongated path, means for depositingmasses of material on said conveyor, a set of upstanding flexiblesupports mounted on the frame at each side of the conveyor, a shaker armat each side of said conveyor and mounted on one of said sets ofsupports, a plurality of flexible members extending between said shakerarms and connected thereto, members extending downwardly from saidflexible members to points adjacent the surface of said conveyor, meansfor reciprocating said shaker arms oppositely whereby said flexiblemembers are flexed to cause the downwardly extending members to moveeccentrically adjacent the conveyor to stir the masses supportedthereby.

8. An apparatus, as claimed in claim 7, in-

cluding a drive shaft, a pair of cranks on said shaft, a connectingmember extending between each crank and one of said shaker arms wherebythe rotation of said shaft causes reciprocating motion of said shakerarms.

9. Apparatus for screening fibrous materials containing lumps,comprising a frame, an endless perforated conveyor mounted on the frame.the perforations in the conveyor being constructed and arranged topermit lump material to pass therethrough and retain fibrous material onthe screen, means to drive the conveyor, means for depositing masses ofsaid material on the conveyor near one end thereof, supporting bowsarranged transversely of the conveyor at intervals along its length,agitating fingers on the bows at spaced intervals along their length,means for supporting and for oppositely oscillating the opposite ends ofsaid bows in directions longitudinally of the conveyor.

10. A method of treating berized asbestos containing lumps comprisingcontinuously screening a mass of the 'asbestos while passing the same ina thin layer through a substantially horizontal and longitudinal path,and agtating said travelling mass to cause the lumps to gravitate to thebottom of the mass and be screened therefrom by continuously subjectingthe mass to a reciprocating stirring action which comprises raking thecontinuously travelling layer of asbestos at the same level andsubstantially adjacent the screening surface both laterally andlongitudinallyV with respect to its path of travel simultaneously atspaced points substantially throughout its screening path, andrecovering the fibrous portion of the mass substantially free of saidseparated screened lumps.

LEE c. PHARO.

